Sound deadening mat



FIG. 1 is a top, perspective view of the sound deadening mat, showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof; and,

FIG. 5 is a side elevation view hereof.

The broken line portion of the drawings defines the bounds of the claimed design and forms no parts thereof. 

CLAIM The ornamental design for a sound deadening mat, as shown and described. 